Malicious PDF — malware analysis report

Static analysis result for SHA-256 86f855ab279b9e2a…

MALICIOUS

PDF

75.4 KB Created: 2021-04-27 09:41:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 2b76f409c388e7bfa13efdc418d3bada SHA-1: 9e171ecc9d27942ec9a3651d3ea05f90a678a29d SHA-256: 86f855ab279b9e2aaafffd6adf49c11501aa5f5885212b892993391e574f44e9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://russian-ice-spb.ru/sites/default/files/webform/files/77599308563.pdf In PDF document text
    • https://www.clinicasfantamaria.ro/sites/default/files/webform/33767122539.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/47147916176.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/49109440539.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/42535902170.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/54305505708.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/93854264345.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/tatesejozamelifat.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/26511902049.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/ralivowu.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/87762274679.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/seliruni.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/85322732160.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/74296331991.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=watts+per+meter+squared+to+decibels+calculatorPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/lezedatabamivija.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B6 5276 bytes
SHA-256: fa57ecc95e80a28cc498f10b61a81385e32e1f1cbb1a59b83414b8c9e071fad6
font_01_sfnt_off0000eba5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA5 11132 bytes
SHA-256: 9390a6e72919d92c9c0ad82f9844d6d393b338ef7133f2c166aef96cdb9c89f7
font_02_sfnt_off000111df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111DF 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176